atovaquone: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
atovaquone: clinical details
Prescribing considerations
- Confirm that PCP is mild-to-moderate and co-trimoxazole intolerance is established.
- Absorption is food-dependent; early diarrhoea or inability to take the suspension with food is associated with lower exposure and treatment failure.
- Evidence is limited in children, older people, non-HIV immunocompromised patients and significant renal or hepatic impairment.
- Review interacting treatments and benzyl alcohol content before prescribing.
Contraindications and cautions
- Known hypersensitivity to atovaquone or any product excipient.
Monitoring
- Monitor clinical and respiratory response; deterioration requires urgent reassessment of diagnosis, severity, absorption and treatment choice.
- Assess food intake, vomiting and diarrhoea throughout treatment.
- Closely monitor older patients and those with significant hepatic or renal impairment.
- Consider blood count, sodium and liver enzymes when clinically indicated.
- Apply interaction-specific monitoring, including zidovudine toxicity and reduced effectiveness of interacting anti-infectives.
Clinical pharmacology
Atovaquone is highly lipophilic, poorly water-soluble and extensively protein-bound. Food markedly increases bioavailability. It inhibits mitochondrial complex III and is predominantly eliminated unchanged in faeces.
Formulation and product differences
- The selected product is an atovaquone-only oral suspension for PCP; it differs from atovaquone–proguanil combination tablets used for malaria.
- The suspension contains benzyl alcohol, must not be diluted and should not be refrigerated or frozen.
- After opening, the selected suspension may be stored for up to 21 days.
atovaquone preparations and strengths
Oral suspension
Route: Oral
Strengths: 750 mg/5 mL
atovaquone interactions
Review all prescribed, non-prescription and complementary treatments before starting atovaquone.
Rifampicin or rifabutin
These substantially reduce atovaquone exposure, so concurrent use is not recommended.
Metoclopramide
It can substantially reduce atovaquone concentrations; another anti-sickness treatment should be considered.
Efavirenz or boosted HIV protease inhibitors
These may markedly lower atovaquone concentrations, so the combination should be avoided where possible.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.